Nanotechnology has been suggested to be one of the critical research endeavors of the early 21st century, as scientists reveal the unique properties of atomic and molecular assemblages built at the nanometer scale. Nanotechnology is often defined as research and technology development at the atomic, molecular, or macromolecular scale, leading to the controlled creation and use of structures, devices, and systems with a length scale of 1 to 100 nanometers (nm). Nanotechnology manifests itself in a wide range of materials (such as carbon nanotubes and gold nanoshells) and particles (such as fullerenes and dendrimers).
Dendrimers are nanoparticles that are composed of a central core and branched monomers. Each dendrimer is globular in shape and includes a large number of end groups known as surface or terminal groups. This configuration is the result of the cyclic manner in which the dendrimer is built. The more branches added to the core, the higher generation of dendrimer formed. For example, polyamidoamine dendrimers are based on an ethylenediamine core, and branched units are constructed from methyl acrylate and ethylenediamine (Tomalia, D. A. et al. Polym. J. 17:117-132, 1985). The specific structure of the dendrimer has been suggested to make dendrimers suitable for a variety of biomedical applications including oligonucleotide transfection agents and drug carriers.
Myeloid derived suppressor cells (MDSCs) are a population of early myeloid cells that are expanded in various disease states including cancer and are capable of suppressing the immune response (Gabrilovich et al., Nat. Rev. Immunol., 9:162-174, 2009 and Greten et al., Int. Immunopharmacol., 11:802-807, 2011, the disclosures of which are incorporated herein by reference in their entireties). IL4Rα is a functional marker of myeloid derived suppressor cells, of tumor associated macrophage, and tumor induced inflammatory monocytes1-4.